Bryant 551B Series, Installation, Start-Up And Service Instructions Manual

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TROUBLESHOOTING
Table 14 — Cooling Troubleshooting
PROBLEM CAUSE REMEDY
Compressor and
condenser fan
will not start. Power failure. Call power company.
Fuse blown or circuit breaker tripped. Replace fuse or reset circuit breaker.
Defective thermostat, contactor, transformer,
or control relay. Replace component.
Insufficient line voltage. Determine cause and correct.
Incorrect or faulty wiring. Check wiring diagram and rewire correctly.
Thermostat setting too high. Lower thermostat setting below room temperature.
High-pressure switch tripped. See problem ‘‘Excessive head pressure.’’
Low-pressure switch tripped. Check system for leaks. Repair as necessary.
Freeze-up protection thermostat tripped. See problem ‘‘Suction pressure too low.’’
Compressor will not
start but condenser
fan runs. Faulty wiring or loose connections in
compressor circuit. Check wiring and repair or replace.
Defective run/start capacitor, overload, start relay Determine cause and replace.
Compressor motor burned out, seized, or
internal overload open.
Determine cause. Replace compressor.
One leg of of 3-phase power dead. Replace fuse or reset circuit breaker. Determine cause.
Compressor cycles
(other than normally
satisfying
thermostat). Refrigerant overcharge or undercharge. Reclaim refrigerant, evacuate system, and recharge to nameplate.
Defective compressor. Replace and determine cause.
Insufficient line voltage. Determine cause and correct.
Blocked condenser. Determine cause and correct.
Defective overload. Determine cause and replace.
Defective thermostat. Replace thermostat.
Faulty condenser-fan motor or capacitor. Replace.
Restriction in refrigerant system. Locate restriction and remove.
Compressor operates
continuously. Dirty air filter. Replace filter.
Unit undersized for load. Decrease load or increase unit size.
Thermostat set too low. Reset thermostat.
Low refrigerant charge. Locate leak; repair and recharge.
Leaking valves in compressor. Replace compressor.
Air in system. Reclaim refrigerant, evacuate system, and recharge.
Condenser coil dirty or restricted. Clean coil or remove restriction.
Scroll compressor
makes excessive
noise. Compressor rotating in the wrong direction. Reverse the 3-phase power leads as described in
Start-Up, page 17.
Excessive head
pressure. Dirty air filter. Replace filter.
Dirty condenser coil. Clean coil.
Refrigerant overcharged. Reclaim excess refrigerant.
Air in system. Reclaim refrigerant, evacuate system, and recharge.
Condenser air restricted or air short-cycling. Determine cause and correct.
Head pressure too low. Low refrigerant charge. Check for leaks; repair and recharge.
Compressor valves leaking. Replace compressor.
Restriction in liquid tube. Remove restriction.
Excessive suction
pressure. High heat load. Check for source and eliminate.
Compressor valves leaking. Replace compressor.
Refrigerant overcharged. Reclaim excess refrigerant.
Suction pressure
too low. Dirty air filter. Replace filter.
Low refrigerant charge. Check for leaks; repair and recharge.
Metering device or low side restricted. Remove source of restriction.
Insufficient evaporator airflow. Increase air quantity. Check filter and replace if necessary.
Temperature too low in conditioned area. Reset thermostat.
Field-installed filter drier restricted. Replace.
Outdoor ambient below 25 F. Install low-ambient kit.
Evaporator fan will
not shut off.
(Sizes 036-060). Time off delay not finished. Wait for 30-second off delay.
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